The objectives of this proposed research are to design and synthesize sulfur containing compounds that stimulate detoxifying enzymes as defenses against carcinogens. The long-term goal is to develop these compounds into cancer chemopreventive agents for human use. To test the activity of the new compounds as potential inhibitors of chemically induce carcinogenesis, a number of rapid screening tests and in vivo tumor inhibition experiments will be carried out. The inhibition of DNA methylation of DNA in the lung and the precancerous lesions in the colon of mice will be determined. The inhibition of lung and colon tumorigenesis in mice by these new compounds will be determined. The results will indicate whether the new compounds may be used as chemopreventive agents in the lung and colon, respectively. PROPOSED COMMERCIAL APPLICATION: The sulfur containing compounds may be developed into cancer chemopreventive agents for human use.